Advances in understanding the relationship between the skull base and larynx with comments on the origins of speech

The position of upper respiratory structures, such as the larynx, has proven to be of great importance in determining an animal’s breathing, swallowing and vocalizing abilities. Studies on living mammals have also shown that the shape of the basicranium is related to the position of the larynx. This information has been of value in using the skull base as a means to reconstruct the upper respiratory tract of fossil hominids. Ongoing comparative and experimental studies of this region are adding new information on the mechanical relationship of the skull base to contiguous areas of the respiratory tract. For example, examination of the region in mammals disparate from humans, such as cetaceans, and experimental work on the region in rats, is adding new data on how the larynx and skull base may functionally interact.